From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-15?Q?Luk=E1=A8_Czerner?= Subject: Re: [PATCH 1/2] libext2fs: fix alloc_allocate_group_table() if the flexbg_offset wraps Date: Tue, 29 Apr 2014 13:02:07 +0200 (CEST) Message-ID: References: <1398694179-18027-1-git-send-email-tytso@mit.edu> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Ext4 Developers List To: "Theodore Ts'o" Return-path: Received: from mx1.redhat.com ([209.132.183.28]:26693 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932384AbaD2LCM (ORCPT ); Tue, 29 Apr 2014 07:02:12 -0400 In-Reply-To: <1398694179-18027-1-git-send-email-tytso@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon, 28 Apr 2014, Theodore Ts'o wrote: > Date: Mon, 28 Apr 2014 10:09:38 -0400 > From: Theodore Ts'o > To: Ext4 Developers List > Cc: Theodore Ts'o > Subject: [PATCH 1/2] libext2fs: fix alloc_allocate_group_table() if the > flexbg_offset wraps > > If the previous block group's inode table ends at the very end of file > system, wrap around to the beginning of the flex_bg. > > This fixes a bug was tickled by: > > mke2fs.conf: > frontload = { > features = extent,huge_file,flex_bg,uninit_bg,dir_nlink,extra_isize,^resize_inode,sparse_super2 > hash_alg = half_md4 > num_backup_sb = 0 > packed_meta_blocks = 1 > inode_ratio = 4194304 > flex_bg_size = 262144 > } > > mke2fs -T frontload /tmp/foo.img 2T > resize2fs -M /tmp/foo.img > resize2fs -M /tmp/foo.img > > Signed-off-by: "Theodore Ts'o" > --- > lib/ext2fs/alloc_tables.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/lib/ext2fs/alloc_tables.c b/lib/ext2fs/alloc_tables.c > index fec9003..bc99943 100644 > --- a/lib/ext2fs/alloc_tables.c > +++ b/lib/ext2fs/alloc_tables.c > @@ -54,8 +54,8 @@ static blk64_t flexbg_offset(ext2_filsys fs, dgrp_t group, blk64_t start_blk, > * Don't do a long search if the previous block > * search is still valid. > */ > - if (start_blk && ext2fs_test_block_bitmap_range2(bmap, start_blk, > - elem_size)) > + if (start_blk && start_blk < ext2fs_blocks_count(fs->super) && > + ext2fs_test_block_bitmap_range2(bmap, start_blk, elem_size)) > return start_blk; Not sure about this, but I just wonder whether this would work with bigalloc file system as well since it is true that we're testing blocks in this condition but in ext2fs_test_block_bitmap_range2() we're searching for a free cluster. -Lukas > > start_blk = ext2fs_group_first_block2(fs, flexbg_size * flexbg); >